【作者】 张雅娴； 王远鹏； 王海涛； 李清彪；

【Author】 Yaxian Zhang;Yuanpeng Wang;Haitao Wang;Qingbiao;College of Chemistry and Chemical Engneering,Xiamen University;

【机构】 厦门大学化学化工学院学院； 厦门大学； 泉州师范学院；

【摘要】 微生物异化Fe(Ⅲ)氧化物还原指以Fe(Ⅲ)氧化物为末端电子受体在厌氧条件下耦联有机物氧化产能的过程,这一过程对多种元素的生物地球化学循环起着重要的影响。然而,异化铁还原过程受到多种因素的影响,目前对微生物Fe(Ⅲ)氧化物还原机制的认识还十分有限。通过异化铁还原过程还可以制备多种多样的铁氧化物,具有广阔的应用前景。为了探究Shewanella xiamenensis与Geobacter sulfurreducens在不同溶解性电子受体中异化铁还原机制的影响,本文采用SEM表征不同体系内Shewanella xiamenensis与Geobacter sulfurreducens菌体形态变化,同时采用XRD对晶体结构Fe(Ⅲ)氧化物α-Fe2O3,γ-Fe2O3及Fe3O4纳米颗粒还原产物进行了初步探索,结果表明,微生物在不同溶解性电子受体的体系内异化铁还原机制不同。更多还原

【Abstract】 Dissimilatroy Fe(Ⅲ) oxide reduction was a process combining Fe(Ⅲ) oxide reduction with the oxidation of organic carbon,which plays an important role on the biogeochemical cycling of many elements. However, dissimilatroy Fe(Ⅲ) oxide reduction could be affected by many factors, such as the type of electron donor, electron acceptor or some foreign materials. Therefore, the mechanism for dissimilatroy Fe(Ⅲ) oxide reduction still remains ambiguous. The study presented here was aimed to investigated Fe(Ⅲ) dissimilatory reduction mechanisms of Shewanella xiamenensis and Geobacter sulfurreducens. Simultaneously, the reduction products were also identified by XRD.Variations of Fe2+ concentration as a function of time showed that Shewanella xiamenensis and Geobacter sulfurreducens reduced 52% and 84% of ferric citrate, respectively. However, Shewanella xiamenensis and Geobacter sulfurreducens reduced approximately 37% and 15% of γ-Fe2O3, respectively. These results illustrated that Shewanella xiamenensis and Geobacter sulfurreducens prefer to use the dissoluble ferric citrate as electron acceptor than the crystal iron oxide. SEM images showed that the surface of both Shewanella xiamenensis and Geobacter sulfurreducens were smooth. On the contrary, Shewanella xiamenensis and Geobacter sulfurreducens produced nanowire pili. The nanoparticle attached to the nanowire pili, composing of a new electron network. Besides, the reduction products showed a complexity of the reduction products of Fe3O4 and Fe(OH)3, firther confirming that crystal iron oxide could not be fully reduced. In summary, the mechanisms of Shewanella xiamenensis and Geobacter sulfurreducens were different in the cultures containing sole electron acceptor of soluble ferric citrate or crystal iron oxide.更多还原